'Eeegh' said the Goat.
That's right. This book is about a goat. A goat who is on a journey on the Endeavour (a picture of the ship is below). She makes friends with a young boy on the ship- he is a master's servant and one of his jobs is to milk the goat. They discover new lands, including Australia.
The story is fictional but based on a real story. The Endeavour really did search for new lands in the 18th century, and the boy, Isaac Manley, really did exist. And there most likely was a goat on board. However, the dialogue between the characters and Isaac's thoughts were made up.